The UCLA Cytometry Core Facility (CCF), a campus-wide resource, provides state-of-the-art instrumentation and expertise at an affordable cost to UCLA researchers needing flow and ELISpot image cytometry. In 1988 the Jonsson Comprehensive Cancer Center established the resource, and since 1991 the Center For AIDS Research (CFAR) has provided additional support. Since 2000 Dr. Jamieson, an accomplished cellular immunologist, directs the CCF and is available to users for consultation. Ms. Schmid, the manager of the facility since 1988, is responsible for the CCF's daily operation and assists Dr. Jamieson with long-term planning. Ms. Schmid is an expert flow cytometrist, well known for her development of flow cytometry methods and her pivotal role in establishing biosafety guidelines for cell sorting. Since 2001 the CCF provides ELISpot assay services under the guidance of Dr. Uittenbogaart, a noted cellular immunologist with extensive expertise in cytokine measurements. The CCF has a single-laser FACScan, a dual-laser FACSCalibur, a three-laser BD LSR I, a modified, dual-laser, five-color FACScan, three, three-laser sorters, an autoMACS magnetic separator, and an off-line data analysis computer. An ImmunoSpot Analyzer, three, free-standing analyzers, and five biological safety cabinets are also available. Cytometric instrumentation is expensive and beyond the budget of most individual researchers. The CCF is easily accessible and is responsible for procurement, daily calibration, maintenance and repair of all instrumentation. CCF personnel have a combined 82 years of flow cytometry and 46 years of cytokine measurement experience. Expertise is available to investigators through one-on-one consultation, classes, a website, poster presentations, and open houses. Ms. Schmid and Dr. Uittenbogaart also work with researchers to adapt or develop assays to enable investigators to pursue research questions in novel ways. CCF services help researchers with varying amounts of experience in cytometry to perform high quality assays with minimal time expenditure. Workshops, seminars, and utilization of new assays ensure that researchers remain on the cutting edge of cytometry without investing their own funds or staff time on keeping current in the latest advances. During the last funding period a total of 250 investigators used the CCF; 40 of those were CFAR/AIDS Institute members representing 38% of use. This documents the role of the CCF in enhancing HIV research at UCLA with its potential contribution to improving the health of HIV-infected patients.